How can i create the same smoke and light effects as in this Bob Ross canvas ? (see image)
Go in to blender. Go to "scene" on your right menues bar. Go to color management and under "view" select: "Filmic Log Encoding Base", then the image will turn ugly, but below exposure and gamma, there is a drop-down menu that says "None" right now. Select that and select the look you want to use. (usually I use medium_high Contrast, but it depends on the scene and how you want it to look.

You would need to add some "volume Scatter" in the scene, and a big smoke simulator to the scene aswell. I think the the smoke in the bob ross image is pretty dense, and would require som work to get it right. But the Volume scatter would add some fog effect to the background without having to use a awful lot of simulated smoke to the scene. The volume scatter is in the "world" tap, where you apply the effect under Volume. Then set the color to all white, and the density to like 0.001. 

The "Filmic Log Encoding Base" makes the light react natural, instead of you inserting 1 million lights into the scene, so you get what you want. 
Hope this helped a bit. :)